The object of this research is to isolate and characterize ion channels from cell membranes. According to work currently in progress these are relatively small (less than 10 to the 4th power MW) molecules whose behavior, i.e. ion conducting properties, may be modified by being embedded in a larger protein matrix which can, for example, act as a receptor for neurotransmitters or drugs. Such reconstitution of a naturally occurring channel-receptor system can take place on an artificial bilayer which thus offers the possibility of analyzing such systems. An example is the acetyl choline activated channel from sources such as the eel eletrroplax. With this, or a similar system, it will be possible to characterize the nicotinic (neuro-muscular) versus the muscarinic (vagal) action of acetylcholine in term of its action on ion permeability. It is believed that this will be a model for more complex control mechanisms.